Front wheel drive vehicles frequently incorporate a MacPherson strut in the front suspension thereof. This strut includes a piston rod mounted at its upper end to a resilient mount on the vehicle body. A coil spring surrounds the piston rod and is seated between a lower spring seat and an upper spring seat located beneath an elastomer pad of the resilient mount. As the car is steered, the spring seats and the coil spring turn together relative to the piston rod and resilient mount. Therefore, it is desirable that there be an anti-friction bearing between the upper spring seat and the resilient mount for superior handling and feel.
The prior art discloses anti-friction bearings in a MacPherson strut.
Cotter et al U.S. Pat. No. 4,248,454 and Shiomi et al U.S. Pat. No. 4,210,343 disclose ground race type ball bearings in a MacPherson strut. German patent application DE No. 3034 743 discloses a ball bearing for a MacPherson strut. The races of the bearing are stamped into the spring seat and into a metal plate molded to the elastomer pad of the resilient mount. Both spring seat and plate would have to be of bearing steel, thick enough to support vehicle load. It would also be difficult to stamp a race of the required curvature into a spring seat. Greene et al U.S. Pat. No. 4,120,543 and Lederman U.S. Pat. No. 4,362,344 disclose modular bearing assemblies for MacPherson struts which have stamped angular contact races. The bearing races of these structures are of a thickness sufficient to support and transfer the imposed loads.